I. Field of the Invention
The present invention relates generally to a tire tread skiving machine or rubber industry.
II. Description of Related Art
In the production of tires for automotive vehicles, a synthetic rubber extrusion is conveyed by a conveyor to a cutting platen. At the cutting platen, a skiving blade performs the cut through the extrusion to form a length of the extrusion corresponding exactly to the required length of tire tread which can be adjusted on the fly for the particular automotive vehicles. Different tire sizes, of course, require different lengths, widths and thickness of tire tread.
Each end of the tire tread extrusion is cut to a precision angle. Consequently, when the tire tread is wrapped around the carcass for the tire the two ends of the extrusion ideally meet in a flush fashion to complete the tread. The overall tire is then vulcanized to complete the manufacture of the tire.
One difficulty of these previously known machines for cutting tire treads from a synthetic rubber extrusion is that the angle of the cut through the extrusion is fixed and cannot be dynamically varied. While that fixed angle is satisfactory for many automotive vehicle tire applications, in some cases, a fixed angle of the cut through the tire tread extrusion is unacceptable. For example, it has been discovered that high-speed tires of the type used by racing cars experience a “speed bump” each time the tire rotates around the junction of the two ends of the tire tread extrusion. This “speed bump” can result not only in excessive tire wear, but also undesirable vibration in the vehicle.
A still further disadvantage of these previously known tire tread skiving machines is that the tire tread extrusion is extremely tacky following the extruding operation. As such, even after the skiving blade formed the cut through the tire tread extrusion, the high tackiness of the ends of the tire tread extrusion around the cut would cause adjacent tire treads to stick together. This, in turn, required that the tire tread extrusion discarded.